我不明白此方法错误

Question

I am making a ciphering program where user enters a word then a pattern then is will scrabble the word.

here is my error:

 1 error found:
  [line: 42]
Error: The method charArray(int) is undefined for the type Cipher

Here is my code:

import java.util.Scanner;

public class Cipher
{
  public static char cipher (int j){
    char[] cipher1 = {'a','b','c','d','e','f','g'};
  j = (int) (Math.random() * cipher1.length);//choose a random element from the array
    return cipher1[j];
  }

  public static void main (String[] args){

    System.out.print("Please type a sentence to be encrypted\n");
    Scanner inputScanner = new Scanner(System.in);
    String input = inputScanner.next();
      System.out.print("please enter");
   input = input.toLowerCase();
    int yu = input.length();
    char[] charArray = input.toCharArray();

        int w=1;
    do{
    try{
    w=2;
      System.out.println("please entrer pattern");
      String hello = inputScanner.next();
      int hello2= Integer.parseInt(hello);
      if(hello2<0){
        System.out.println("please enter proper number");
        w=1;
      }
    }catch (NumberFormatException f){
      System.out.println("please enter proper number");
    }

    }while (w==1);

    System.out.print("your encrypted code is ");

    for(int i = 0; i < yu; i++){
    System.out.print(charArray(i)); //THIS IS WHERE ERROR IS HIGHLIGHITNG
    for(int q = 0; q <= w; q++){
    System.out.print( cipher(1));
    }
    }
  }
}

Answer 1

The error seems to be occurring because there isn't a method called charArray in your Cipher class. I suspect what you really want is to get the elements from an array called charArray that you have defined earlier in your code. So the syntax should be charArray[i] to get element at index i.

Answer 2

Yes, the method charArray(int) has not been defined here.

When you use are trying to print charArray[i] you have accidentally written charArray(i)

Instead of accessing the value at position i it is trying to execute a method that doesn't exist. Just change () brackets to [] ones and you will see that your error disappears.

Answer 3

when you write it like charArray(i) it will try to call a method named charArray passing i as argument to it(which is not defined actually in your case)

while when you say charArray[i] it will understand that you want to access i th element of charArray

so you need to change

System.out.print(charArray(i));

to

System.out.print(charArray[i]);